No Keyway in my 3 1\2 hp briggs

[getting kart smart]

I've got a briggs motor with no keyway on the shaft. I am planning on using my dremel to cut out a 3\16 keyway to secure the clutch. Has anybody ever attempted this or is there a better way without taking it to a machine shop?

 

[tundrabeagle3]

i have attempted it with bad luck. the key way has to be perfect or else it wont work. if you don't want to machine it then i would recommend changing the crankshaft.

 

[OzFab]

i have attempted it with bad luck. the key way has to be perfect or else it wont work. if you don't want to machine it then i would recommend changing the crankshaft.

The only way to do this is on a mill operated by someone experienced

 

[Doc Sprocket]

I have done it. You have to be dead slow and careful, checking your work often. Make no mistake- it's absolutely painstaking, but do-able.

You have got to mark it perfectly, using a jig or square, or both. Using both a key, and a keyed hub, check your progress frequently.

 

[r_chez_08]

Any pics toystory? Fair effort there!
I would reccomend getting a quite from a machine shop, but first, I have a crank from a 3hp bushing block flatty, you can have it for $5 + postage if it would fit.

 

[Doc Sprocket]

Any pics toystory? Fair effort there!

Naw, I did it years ago on a machine I was fixing. The only replacement shaft I could lay hands on at the time wasn't keyed. Did not take pictures at the time, didn't have a camera in my phone. Needless to say, it took quite awhile.

 

[getting kart smart]

What if I were too drill small holes in the shaft where the set screws go. Screw the setscrews into the holes on the shaft? It's only a 3.5 hp. but it seems to me that this would be a high torque spot and my thinking says it would tare those little set screws up.

 

[souperman000]

http://www.diygokarts.com/vb/showthread.php?t=19167&highlight=keyway+toystory

Turns out Toystory ended up doing one! he was very careful though.

 

[Doc Sprocket]

Turns out Toystory ended up doing one! he was very careful though.

That's the only way to fly! And yes- the setscrews would shear.

 

[Russ2251]

I've got a briggs motor with no keyway on the shaft. I am planning on using my dremel to cut out a 3\16 keyway to secure the clutch. Has anybody ever attempted this or is there a better way without taking it to a machine shop?

Easily done with patience and has saved me mucho dinero.
Keep in mind that it does not have to be "dead nuts" perfect. In fact this keyway is far longer than is required.
I have lost count as to how many times I have done it...at least 4 or 5. Gets easier with practice.
I say go for it. If I can do it, most certainly you or anyone else can.
Before and after photos: